Foucault's Pendulum

Foucault's Pendulum is Umberto Eco's novel of a few Milanese book editors who are bored with their work. To pass the time they cook up an elaborate hoax that connects the medieval Knights Templar with occult groups across the centuries. Becoming obsessed with their creation, they produce a map. The map indicates the geographical point from which all the powers of the earth can be controlled. It's a point located in Paris, France, at Foucault’s Pendulum.
 
But in a fateful turn, the joke becomes all too real. When occult groups get wind of the Plan, they go so far as to kill one of the editors. In doing so they hope to gain control of the earth. Orchestrating these and other diverse characters into his multilayered semiotic adventure, Eco has predicted too well. We now have QAnon and other weirdos who trade under other names. It's a wild read and one of my favorite works of Eco's.